


Improbable Anatomy: Tachyglossidae

by MlleMusketeer



Category: The Transformers (IDW Generation One)
Genre: Bottom Megatron, Creative genitalia, Dick ideas from nature, Escapade 2020, M/M, PWP, Rodimus has an echidna dick and is filled with joy, Spike Modifications (Transformers)
Language: English
Status: Completed
Published: 2020-02-24
Updated: 2020-02-24
Packaged: 2021-02-19 04:09:39
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,110
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22871614
Author URL: https://archiveofourown.org/users/MlleMusketeer/pseuds/MlleMusketeer
Summary: Rodimus got a mod. Rodimus demonstrates the mod. Megatron has a very good day.Enabled by Escapade 2020's monsterfucker panel.
Relationships: Megatron/Rodimus | Rodimus Prime
Comments: 11
Kudos: 155





	Improbable Anatomy: Tachyglossidae

"Ta-DAAAA!"

Rodimus Prime stood proudly in the doorway between the hab-suite and the washracks, hands on hips and crotch thrust forward with an immense slag-eating grin on his face. Megatron, sitting on the berth, froze, optics immediately drawn to where Rodimus probably _meant_ them to be drawn.

"What the fuck is that?" Sometimes human curses sounded far dirtier than Cybertronian and sometimes that was appropriate, like right now.

"It's my spike!" said Rodimus, enthusiastically, as his spike described a slow, writhing path through the air, totally independent of Rodimus's hips. "It's prehensile! It feels great! I know that because it can go up my own—"

Megatron raised a hand as Rodimus's spike started to suit words to action. "All right. I get the idea. _Why_ did you make your spike prehensile and…" he reset his vocalizer, " _significantly larger?_ And with a uh."

 _A uh_ was where his words to describe the spike ran out, because the end of Rodimus's new spike split into four parts, a broad, fanlike head with what looked like four separate transfluid channels. As he watched, the four heads moved like suckers.

"Hedonia," said Rodimus, as if it explained everything.

Megatron stared at it and reset his vocalizer. More than once.

"Also, you're a big mech!" Rodimus grinned at him. "And I want to make you feel _really good."_

"Um," said Megatron again, staring. Still lost for words. Before Rodimus could get insecure—and he could see the beginnings of worry on the other mech's face—he popped his panels in lieu of a response.

" _Niiice,_ " said Rodimus. "C'mere."

Megatron went, sliding down onto his knees in front of Rodimus and getting an almost literal eyeful of Rodimus's new spike. It didn't seem it was entirely under conscious control yet. He ended up grasping the shaft firmly to keep it in place so he could get his mouth around the head. Rodimus gasped and grabbed at the back of his helmet. "Oh yeah, perfect, get me ready, your mouth is so good!"

Megatron snorted a laugh around the spike, then moaned as Rodimus's hips hitched forward. Unlike his old spike, this one was borderline uncomfortable to take, not the easy slip just past the back of his throat. He reached down to his own spike, taking it in hand and rubbing the slit with a thumb. The spike in his mouth was big and thick and firm. He was already imagining it in his valve.

"Don't get carried away there," said Rodimus, gasping. "Still gotta get this up your sweet little valve. Oh frag, that's good. Primus you're so good at sucking spike, Megs." His hips bucked forward a few more times, then, evidently mastering himself, he pulled out of Megatron's mouth.

"All right. All right. Can't keep this up if you keep that up, if you know what I mean. And you want me to keep this up." Rodimus winked at him. "Prehensile means it can do this."

The tip of his spike curved up, then flattened back in a come-hither gesture. Megatron's eyes fixed on it. Rodimus, seeing his attention was thoroughly captured, flexed the shaft upward, undulating it a few times as if rubbing against an invisible ceiling node. "How about you bend over the berth and I frag you silly?"

Megatron scrambled to bend over the berth, his mouth dry. Rodimus's fingers pressed against his opening, pushing his fingers inside. Megatron gasped, turning his face into the berth covers, cheeks heating.

"Don't hide from me," said Rodimus, putting a hand on his helmet and turning his head back. "I wanna see your face when I get this bad boy into you."

Megatron gave him a very suspicious look in return.

Rodimus lined up his spike and pushed into him before he could do anything more than look and Megatron gasped, hands fisting in the berth covers as every node around his entrance was instantly stimulated. He felt it moving inside of him and then Rodimus paused and did that come hither gesture again and he yelped.

"Was that a good squeal or a bad one?"

Megatron wouldn't have described that as a squeal, but… "Good," he grumbled.

"Great!" said Rodimus, and kept doing it.

To his horror, Megatron was very quickly reduced to gasps and moans and whimpering into the covers. He was just on the edge of getting used to it when Rodimus went, "All right. Okay. I can't—I can't hold off anymore," and grabbed his hips and yanked Megatron all the way onto his huge, superbly textured spike, the little plates catching and dragging on Megatron's internal sensors, _all of them_ , and then he grabbed the back of Megatron's neck with his free hand, like a dominating bite, and Megatron's optics went wide and unfocused and his world narrowed down to the hand on his neck and the hand on his hip and the spike inside him where Rodimus was ruthlessly taking him, gasping his name with a whine of delierous pleasure.

The spike inside him undulated against his ceiling node, hitting it firmly every time and pressing and rubbing slickly, and then one of the sucker-heads around one of Rodimus's transfluid channel found it and fastened on it and Megatron screamed.

"That's a good scream, right?" said Rodimus. Megatron, gasping for breath, nodded frantically and whimpered as it suckled harder.

"Cool," said Rodimus. "Cool cool cool—oh Primus Megatron I'm gonna…" His hand dropped quickly to Megatron's node, already slick with the fluids dribbling from his valve, rubbing quick and light as his spike moved fast and hard.

Megatron overloaded almost instantly. Rodimus moved his fingers from his node to his hips, bucking a few more times inside him before overloading with a wail and producing a simply improbable quantity of transfluid.

They lay there, gasping, for a while.

Then Rodimus rolled off Megatron's back, the spike slowly depressurizing and sliding into its housing. Feeling completely strutless, Megatron flopped onto his back.

"I still think," he said after several minutes, Rodimus's hand comforting on his thigh, "it's a completely ridiculous mod."

"That was a lot of screaming for thinking it was a completely ridiculous mod," said Rodimus, with no vitriol in it.

"It's completely ridiculous," Megatron said. "I'm going to need you to demonstrate its use a few more times before I can make a decision on whether its absurdity is overcome by its usefulness."

"How many's a few more times?" asked Rodimus, sounding hopeful.

"Mmm," said Megatron, closing his optics. "At least a dozen. Over the next week."

"Two dozen," said Rodimus, with satisfaction, and burrowed his face into Megatron's shoulder and went to sleep like that.


End file.
